diff -r cb2891afe526 -r 998e8def9676 src/demo/lp_maxflow_demo.cc
--- a/src/demo/lp_maxflow_demo.cc	Fri Apr 22 16:20:12 2005 +0000
+++ b/src/demo/lp_maxflow_demo.cc	Fri Apr 22 17:47:01 2005 +0000
@@ -1,13 +1,26 @@
-#include<lemon/lp_glpk.h>
 #include<lemon/graph_reader.h>
 #include<lemon/list_graph.h>
 
+
+#ifdef HAVE_GLPK
+#include <lemon/lp_glpk.h>
+#elif HAVE_CPLEX
+#include <lemon/lp_cplex.h>
+#endif
+
 using namespace lemon;
 
+#ifdef HAVE_GLPK
+typedef LpGlpk LpDefault;
+#elif HAVE_CPLEX
+typedef LpCplex LpDefault;
+#endif
+
+
 template<class G,class C>
 double maxFlow(const G &g,const C &cap,typename G::Node s,typename G::Node t)
 {
-  LpGlpk lp;
+  LpDefault lp;
   
   typedef G Graph;
   typedef typename G::Node Node;
@@ -17,7 +30,7 @@
   typedef typename G::OutEdgeIt OutEdgeIt;
   typedef typename G::InEdgeIt InEdgeIt;
   
-  typename G::template EdgeMap<LpGlpk::Col> x(g);
+  typename G::template EdgeMap<LpDefault::Col> x(g);
   lp.addColSet(x);
   
   for(EdgeIt e(g);e!=INVALID;++e) {
@@ -26,22 +39,23 @@
   }
 
   for(NodeIt n(g);n!=INVALID;++n) if(n!=s&&n!=t) {
-    LpGlpk::Expr ex;
+    LpDefault::Expr ex;
     for(InEdgeIt  e(g,n);e!=INVALID;++e) ex+=x[e];
     for(OutEdgeIt e(g,n);e!=INVALID;++e) ex-=x[e];
     lp.addRow(ex==0);
   }
   {
-    LpGlpk::Expr ex;
+    LpDefault::Expr ex;
     for(InEdgeIt  e(g,t);e!=INVALID;++e) ex+=x[e];
     for(OutEdgeIt e(g,t);e!=INVALID;++e) ex-=x[e];
     lp.setObj(ex);
   }
   lp.max();
 
+#ifdef HAVE_GLPK
   lp.presolver(true);
-  
   lp.messageLevel(3);
+#endif
 
   lp.solve();